The jury was expected to begin deliberations later Friday on charges against Thornton, 36, and Sgts. Jason Griffis and Charles Brown, both 28. They face possible life sentences if convicted.

The former guards are also accused of conspiracy to commit aggravated battery, battery on an inmate, and official misconduct. Five other corrections officers will stand trial later.

Fletcher said Thornton, who faces an additional charge of accessory after the fact, did nothing wrong.

"Capt. Thornton must, did and continued to rely on the information supplied by the officers who worked him," she said.

Valdes died in July 1999 at Florida State Prison after what prosecutors allege was two violent confrontations with corrections officers.

During closing arguments Thursday, prosecutor Marc Peterson said that regardless of whether Thornton, Griffis and Brown fatally stomped Valdes, they had a duty to protect him. If they didn't, they are guilty, he said.

"When they don't, and they don't because you find they have an ill will toward him and they don't care about him and they have an indifference to his life, that rises to the level of second-degree murder," Peterson told jurors.

The former guards' attorneys argued that prosecutors never proved their clients' guilt. They said the prosecution's witnesses _ mostly other inmates or guards _ were either bought or coerced. Many received deals for their testimony, they said.

"I am confident … you will bring a verdict that speaks the truth in the case, which is not guilty," said defense attorney Ted Curtis.

Valdes, 36, was sentenced to death for the 1987 murder of a corrections officer while trying to free an inmate from a prison van outside a West Palm Beach doctor's office.